BoilerFaultCodes.com
neon illuminated (flashing with cross symbol) High Lockout

Your boiler has failed to ignite the gas burner and has gone into a safety lockout mode.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Ignition failure - The burner has failed to light. Turn selector to the reset position R and hold for at least 2 seconds.

What causes this fault?

This fault occurs when the boiler tries to light the gas but cannot detect a stable flame after several attempts. The most common reasons are a worn-out ignition spark that can no longer reach the burner or a faulty gas valve that isn't releasing fuel into the combustion chamber.

Typical repair cost £100-280 (including labour)

DIY fix possible

Check that your gas supply is turned on and you have credit on your meter.Turn the selector switch to the 'R' (reset) position and hold it for at least 2 seconds.Ensure there are no blockages at the external flue pipe (the white pipe outside your home).

Find a Gas Safe engineer

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